Mg-based alloys are often considered potential lightweight structural alloys for transportation applications in efforts to improve efficiency. However, poor mechanical strength and ductility have long been impediments to wide industrial use of Mg alloys. Some Mg-based alloys have been observed to form a ternary precipitate exhibiting order with long periods along the c-axis. Referred to as long period stacking ordered (LPSO) structures, these precipitates, and their resulting high strength, have since been observed in a variety of ternary Mg systems. However, LPSO systems typically contain at least 1 at. % rare earth (RE) elements, making such alloys prohibitively expensive for high-volume industrial applications.